From: Martin Mares <mj@ucw.cz>
Date: Sun, 1 Apr 2018 22:16:32 +0000 (+0200)
Subject: Trivial auto-generated help
X-Git-Tag: v0.1~36
X-Git-Url: http://mj.ucw.cz/gitweb/?a=commitdiff_plain;h=2bc1cb0f16c0871198cad5f787656b6c9dc2f842;p=paperjam.git

Trivial auto-generated help
---

diff --git a/jam.h b/jam.h
index 2917aef..c985502 100644
--- a/jam.h
+++ b/jam.h
@@ -105,6 +105,7 @@ vector<page *> run_command_list(list<cmd *> &cmds, vector<page *> &pages);
 // parse.cc
 
 void parse(const char *in, list<cmd *> &cmds);
+void help();
 
 // cmds.cc
 
diff --git a/paperjam.cc b/paperjam.cc
index fa2c6dd..ba2bb3b 100644
--- a/paperjam.cc
+++ b/paperjam.cc
@@ -148,6 +148,12 @@ static void process(list<cmd *> &cmds, const char *in_name, const char *out_name
 
 int main(int argc, char **argv)
 {
+  if (argc <= 1 || argc > 1 && !strcmp(argv[1], "--help"))
+    {
+      help();
+      return 0;
+    }
+
   if (argc != 4)
     {
       fprintf(stderr, "Usage: paperjam <commands> <input> <output>\n");
diff --git a/parse.cc b/parse.cc
index 3719a4e..1869b3a 100644
--- a/parse.cc
+++ b/parse.cc
@@ -459,3 +459,29 @@ void parse(const char *in, list<cmd *> &cmds)
   debug_cmds(cmds);
   instantiate(cmds);
 }
+
+void help()
+{
+  for (int i=0; cmd_table[i].name; i++)
+    {
+      const cmd_def *def = &cmd_table[i];
+      printf("%s\n", def->name);
+
+      const arg_def *arg = def->arg_defs;
+      static const char * const type_names[] = {
+	"string", "int", "double", "dimen"
+      };
+      while (arg->name)
+	{
+	  printf("\t%s (%s)%s%s\n",
+	    arg->name,
+	    type_names[arg->type & AT_TYPE_MASK],
+	    (arg->type & AT_MANDATORY) ? " [mandatory]" : "",
+	    (arg->type & AT_POSITIONAL) ? " [positional]" : "");
+	  arg++;
+	}
+
+	if (def->has_pipeline)
+	  printf("\t{ pipeline }\n");
+    }
+}